For centuries long hair has been a desirable attribute To achieve this straightening devices are sold that mechanically lengthen and straighten the hair, a selection of such devices are disclosed in EP 0 511 892 and WO12/32381. An alternative to the above mechanical approach to lengthen the hair is to stimulate hair growth using chemical hair growth stimulants, such products are disclosed in EP 0 897 712 and WO92/07877.
The use of xanthines in hair and skin pigmentation is described in U.S. Pat. No. 5,470,579. EP 0 728 472 discloses xanthines in skin care compositions to reduce signs of cellulite.
U.S. Pat. No. 4,931,066 discloses that xanthines can be used together with other compounds in hair dyeing.
Xanthines have also been claimed as being useful in the treatment of hair loss. For example, WO 85/05270, EP 0 325 969, WO 84/04038, FR 2 751 541 and WO 85/05272 all disclose hair loss treatments containing caffeine or theophylline as phosphodiesterase inhibitors. A hair nourishing lotion or shampoo containing caffeine and the hair loss treatment compound minoxidil is described in JP 04-193821.
The present application discloses formulations and processes for lengthening hair. The invention has the further advantages that it prevents the hair frizzing and increasing in volume. Yet another advantage is that it increases the hair's susceptibility and hold to styling in humid conditions.